Curable composition, and resin composition for stereolithography prepared therefrom

ABSTRACT

To provide a curable composition that is readily modeled with low viscosity and excellent curing capability in modeling by stereolithography, and provides a cured article excellent in toughness and water resistance, and a resin composition for stereolithography prepared therefrom. To provide a resin composition for stereolithography that is favorable particularly for a dental mouthpiece and a denture base material. A curable composition containing 79.0 to 99.0% by mass of a polymerizable monomer (a), 0.1 to 10.0% by mass of a photopolymerization initiator (b), and 0.01 to 20.0% by mass of a compound (c) represented by the following general formula (I):

TECHNICAL FIELD

The present invention relates to a curable composition and a resincomposition for stereolithography prepared therefrom. More specifically,the present invention relates to a resin composition forstereolithography that is readily modeled with low viscosity in modelingby stereolithography, and is capable of providing a stereoscopic modeledarticle excellent in toughness and water resistance. A stereoscopicmodeled article obtained by the present invention is favorableparticularly for a dental mouthpiece and a denture base material.

BACKGROUND ART

PTL 1 describes a method of providing a stereoscopic modeled article byrepeating an operation including supplying a required amount ofcontrolled optical energy to a liquid photocurable resin for curing intoa thin layer, further supplying a liquid photocurable resin thereon, andthen irradiating with light under control for curing and laminating intoa thin layer form, i.e., a so-called an optical stereoscopic modelingmethod. PTL 2 describes a basic practical method thereof, and sincethen, many proposals relating to the optical stereoscopic modelingtechnique have been made.

As a representative method for optically producing a stereoscopicmodeled article, a method referred to as vat stereolithography has beenemployed, which repeats a lamination operation including irradiating aliquid surface of a liquid photocurable resin composition placed in avat with an ultraviolet ray laser controlled with a computer to providea prescribed pattern, so as to cure in a prescribed thickness, resultingin a cured layer, then supplying the liquid photocurable resincomposition in an amount corresponding to one layer to the cured layer,and similarly irradiating with ultraviolet ray laser to cure, resultingin a continuous cured layer, and thus produces a stereoscopic modeledarticle having the final shape. The method is receiving increasingattention in recent years since a target stereoscopic modeled articlecan be produced with high accuracy in a convenient manner within arelatively short period of time even though the modeled article has aconsiderably complicated shape.

A stereoscopic modeled article obtained by the stereolithography is nowbeing expanded from a simple conceptual model to a trial model, aprototype model, and the like, and associated thereto, the stereoscopicmodeled article is increasingly demanded to have excellent modelingaccuracy. Furthermore, the stereoscopic modeled article is also demandedto have excellent characteristics corresponding to the applicationthereof, in addition to the aforementioned characteristics. In the fieldof dental materials, in particular, a dental mouthpiece and a denturebase material are different in shape for each patient and havecomplicated shapes, and therefore the application of stereolithographythereto is being expected.

The dental mouthpieces include a dental aligner mounted on a row ofteeth for orthodontics, a dental splint mounted for jaw positioncorrection, a mouthpiece mounted on a row of teeth during sleeping atnight for treating the sleep apnea syndrome, a mouthpiece mounted on arow of teeth for suppressing abrasion of teeth due to clenching, and amouthpiece mounted in an oral cavity for reducing external injuriesoccurring due to an external force applied to teeth or jawbone duringsports activities and for protecting the stomatognathic system and thebrain. The use of the dental mouthpieces is rapidly spread inorthodontics in recent years due to the good esthetics and the casualdetachability thereof. The sleep apnea syndrome is receiving attentionin the medical field, and the use of the dental mouthpieces is rapidlyspread as a therapeutic device therefor.

A denture base material is used in the gingiva portion of a denturemounted due to loss of teeth. Due to the increase of the elderlypopulation in recent years, the demand of dentures is being rapidlyincreased.

The dental mouthpiece and the denture base material are commonlydemanded to have toughness and water resistance. With poor toughness,the wearing feeling may be deteriorated, and an impact of an externalforce or occlusion is applied directly to the jawbone. Furthermore,there may be a problem that the frequent remaking is required due to thefragility thereof. Moreover, there may be a problem that thedeterioration of the water resistance may decrease the mechanicalcharacteristics, resulting in loss of the orthodontic force or the shockabsorbability, and lack of practicality due to fragility.

In the production of the dental mouthpiece, the denture base material,and the sleep apnea syndrome treatment device, it is generally necessaryto take an impression of the oral cavity, but the problems have beennoted that the discomfort thereof becomes a burden on patients, and anexpert technical operation is required therefor. According to thedevelopment of digital technologies in recent years, there is an attemptto take the impression by optically scanning the oral cavity, and inmodeling, there is an attempt to apply the optical stereoscopicmodeling. A photocurable resin composition is used for modeling, but aresin composition exhibiting flexibility and water resistance generallytends to use a monomer having low polarity resulting in low curingcapability, resulting in a tendency that the cured article has adeteriorated mechanical strength, and particularly in opticalstereoscopic modeling, since the light irradiation time is extremelyshort, and the resin composition is exposed to oxygen in modeling everylayer, the curing thereof tends to be insufficient, which has made itdifficult to achieve all the mechanical strength, the toughness, and thewater resistance simultaneously. Furthermore, while the resincomposition necessarily has viscosity that enables modeling, there is aproblem that the curing capability is deteriorated in the case where amonomer having a small molecular weight is used for decreasing theviscosity, but a monomer exhibiting the mechanical strength frequentlyhas high viscosity deteriorating the modeling capability.

Under the circumstances, as a technique enabling optical stereoscopicmodeling with the excellent modeling accuracy, and the excellentmechanical strength and swelling resistance of the cured article, forexample, PTL 3 proposes a resin composition for optical stereoscopicmodeling containing as essential components an α,β-unsaturated doublebond group-containing compound having both a (meth)acryloyl group and analkenyl group.

CITATION LIST Patent Literatures

-   PTL 1: JP 56-144478 A-   PTL 2: JP 60-247515 A-   PTL 3: JP 2015-10168 A

SUMMARY OF INVENTION Technical Problem

PTL 3 does not specifically describe about the enhancement of thetoughness and the water resistance of the photocurable resin compositiondescribed therein.

An object of the present invention is to provide a curable compositionthat is readily modeled with low viscosity and excellent curingcapability in modeling by stereolithography, and provides a curedarticle excellent in toughness and water resistance, and a resincomposition for stereolithography prepared therefrom. Another objectthereof is to provide a resin composition for stereolithography that isfavorable particularly for a dental mouthpiece and a denture basematerial.

Solution to Problem

The present invention relates to the following items.

-   -   [1] A curable composition containing    -   79.0 to 99.0% by mass of a polymerizable monomer (a),    -   0.1 to 10.0% by mass of a photopolymerization initiator (b), and    -   0.01 to 20.0% by mass of a compound (c) represented by the        following general formula (I):

wherein X¹, X², and X³ each represent a chalcogen atom; R¹ and R² eachindependently represent at least one kind selected from the groupconsisting of a hydrogen atom, an alkyl group having 1 to 18 carbonatoms, an alkenyl group having 2 to 18 carbon atoms, and an aralkylgroup; R³ and R⁴ each independently represent at least one kind selectedfrom the group consisting of a hydrogen atom, an alkyl group having 1 to6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an arylgroup, and an aralkyl group; R⁵ and R⁶ each independently represent atleast one kind selected from the group consisting of a hydrogen atom, analkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6carbon atoms, an aryl group, and an aralkyl group; R⁷ represents ahydrogen atom or a methyl group; R⁸ represents at least one kindselected from the group consisting of a hydrogen atom, an alkyl grouphaving 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms,a (meth)acryloyl group, a 4-vinylphenyl group, an aryl group, and anaralkyl group; and n represents an arbitrary integer, provided that R³,R⁴, R⁵, and R⁶ are not bonded to each other to form a ring structure.

-   -   [2] The curable composition according to the item [1], wherein        the compound (c) is a compound represented by the following        general formula (II):

wherein R⁹ and R¹⁰ each independently represent at least one kindselected from the group consisting of a hydrogen atom, an alkyl grouphaving 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms,an aryl group, and an aralkyl group; R¹¹ and R¹² each independentlyrepresent at least one kind selected from the group consisting of ahydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenylgroup having 2 to 6 carbon atoms, an aryl group, and an aralkyl group; nrepresents an arbitrary integer, provided that R³, R⁴, R⁵, R⁶, R⁹, R¹⁰,R¹¹, and R¹² are not bonded to each other to form a ring structure; andR³ to R⁸ have the same definitions as above.

-   -   [3] The curable composition according to the item [2], wherein        in the general formula (II), R³, R⁴, R⁹, and R¹⁰ each        independently represent at least one kind selected from the        group consisting of an alkyl group having 1 to 6 carbon atoms,        an alkenyl group having 2 to 6 carbon atoms, an aryl group, and        an aralkyl group.    -   [4] The curable composition according to the item [2] or [3],        wherein in the general formula (II), R⁸ represents a hydrogen        atom or a (meth)acryloyl group.    -   [5] The curable composition according to any one of the items        [2] to [4], wherein in the general formula (II), n=1.    -   [6] The curable composition according to any one of the items        [1] to [5], wherein the polymerizable monomer (a) contains a        polymerizable monomer (a)-1 containing plural polymerizable        groups.    -   [7] The curable composition according to the item [6], wherein        the polymerizable monomer (a)-1 contains a urethanated        (meth)acrylic compound (a)-1α.    -   [8] The curable composition according to any one of the items        [1] to [7], wherein the polymerizable monomer (a) contains a        monofunctional polymerizable monomer (a)-2.    -   [9] The curable composition according to the item [8], wherein        the monofunctional polymerizable monomer (a)-2 contains a ring        structure.    -   [10] A resin composition for stereolithography containing the        curable composition according to any one of the items [1] to        [9].    -   [11] The resin composition for stereolithography according to        the item [10], wherein the resin composition further contains        inorganic particles (d).    -   [12] A stereolithography resin cured article containing a cured        article of the resin composition for stereolithography according        to the item [10] or [11].    -   [13] A dental material containing a cured article of the resin        composition for stereolithography according to the item [10] or        [11].    -   [14] A dental mouthpiece containing a cured article of the resin        composition for stereolithography according to the item [10] or        [11].    -   [15] A denture base material containing a cured article of the        resin composition for stereolithography according to the item        [10] or [11].    -   [16] A medical material containing a cured article of the resin        composition for stereolithography according to the item [10] or        [11].    -   [17] A sleep apnea syndrome treatment device containing a cured        article of the resin composition for stereolithography according        to the item [10] or [11].    -   [18] A method for producing a stereoscopic modeled article by an        optical stereoscopic modeling method, including using the resin        composition for stereolithography according to the item [10] or        [11].    -   [19] A compound represented by the following general formula        (III):

wherein R represents a hydrogen atom or a methyl group; R¹ and R² eachindependently represent at least one kind selected from the groupconsisting of a hydrogen atom, an alkyl group having 1 to 18 carbonatoms, an alkenyl group having 2 to 18 carbon atoms, and an aralkylgroup; R³ and R⁴ each independently represent at least one kind selectedfrom the group consisting of a hydrogen atom, an alkyl group having 1 to6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an arylgroup, and an aralkyl group; R⁷ represents a hydrogen atom or a methylgroup; and n represents an integer of 2 or more.

Advantageous Effects of Invention

The curable composition and the resin composition for stereolithographyprepared therefrom according to the present invention are readilymodeled with low viscosity and excellent curing capability in modelingby stereolithography, and provide a cured article excellent in toughnessand water resistance, and therefore can be favorably applied to variousdental materials, particularly to a dental mouthpiece, a denture basematerial, and the like.

DESCRIPTION OF EMBODIMENTS

The curable composition of the present invention contains apolymerizable monomer (a), a photopolymerization initiator (b), and acompound (c) in the prescribed amounts. The resin composition for astereolithography containing the curable composition is readily modeledwith low viscosity and excellent curing capability in modeling bystereolithography, and provides a cured article excellent in toughnessand water resistance.

In the description herein, the upper limit values and the lower limitvalues of the numerical ranges (for example, the contents of thecomponents, the values calculated from the components, and the propertyvalues) may be arbitrarily combined.

Polymerizable Monomer (a)

The polymerizable monomer (a) used in the present invention ispreferably a radical polymerizable monomer. Specific examples of theradical polymerizable monomer as the polymerizable monomer (a) include a(meth)acrylate based polymerizable monomer; a (meth)acrylamide basedpolymerizable monomer; ester compounds of α-cyanoacrylic acid,(meth)acrylic acid, α-haloacrylic acid, crotonic acid, cinnamic acid,sorbic acid, maleic acid, itaconic acid, and the like; a vinyl estercompound; a vinyl ether compound, a mono-N-vinyl derivative; and astyrene derivative. Among these, a (meth)acrylate based polymerizablemonomer and a (meth)acrylamide based polymerizable monomer are preferredfrom the standpoint of the curing capability. These compounds may beused alone or as a combination of two or more kinds thereof.

Examples of the polymerizable monomer (a) in the present inventioninclude a polymerizable monomer (a)-1 containing plural polymerizablegroups and a monofunctional polymerizable monomer (a)-2. Thepolymerizable monomer (a)-1 containing plural polymerizable groups ispreferably used from the standpoint of the curing capability, themonofunctional polymerizable monomer (a)-2 is preferably used from thestandpoint of the easiness in achieving low viscosity, and both thepolymerizable monomer (a)-1 containing plural polymerizable groups andthe monofunctional polymerizable monomer (a)-2 are preferably used fromthe standpoint of the toughness.

The polymerizable monomer (a)-1 containing plural polymerizable groupsis preferably bifunctional from the standpoint that the cured article isexcellent in toughness.

Examples of the polymerizable monomer containing plural polymerizablegroups include a polymerizable monomer containing a urethane bond andplural polymerizable groups (i.e., a urethanated (meth)acrylic compound(a)-1α) and a polymerizable monomer containing plural polymerizablegroups containing no urethane bond, and the urethanated (meth)acryliccompound (a)-1α is preferably contained from the standpoint of thetoughness.

The urethanated (meth)acrylic compound (a)-1α can be readilysynthesized, for example, by subjecting a polyol having a polymerskeleton described later, a compound having an isocyanate group (—NCO),and a (meth)acrylate compound having a hydroxy group (—OH) to additionreaction. The urethanated (meth)acrylic compound (a)-1α can also bereadily synthesized, for example, by subjecting a (meth)acrylatecompound having a hydroxy group and a lactone or an alkylene oxide toring-opening addition reaction, and then subjecting the resultingcompound having a hydroxy group at one end thereof and a compound havingan isocyanate group to addition reaction.

The urethanated (meth)acrylic compound (a)-1α is preferably a(meth)acrylate having in one molecule thereof at least one structureselected from the group consisting of a polyester, a polycarbonate, apolyurethane, a polyether, a poly(conjugated diene), and a hydrogenatedpoly(conjugated diene), and a urethane bond. In the structures, examplesof the polyester include a polymer of phthalic acid and an alkylenediolhaving 2 to 12 carbon atoms, a polymer of adipic acid and an alkyleneglycol having 2 to 12 carbon atoms, a polymer of sebacic acid and analkylene glycol having 2 to 12 carbon atoms, a polymer of maleic acidand an alkylenediol having 2 to 12 carbon atoms, a polymer ofβ-propiolactone, a polymer of γ-butyrolactone, a polymer ofδ-valerolactone, a polymer of ε-caprolactone, and copolymers thereof.Examples of the polycarbonate include a polycarbonate derived from analiphatic diol having 2 to 12 carbon atoms, a polycarbonate derived frombisphenol A, and a polycarbonate derived from an aliphatic diol having 2to 12 carbon atoms and bisphenol A. Examples of the polyurethane includea polymer of an aliphatic diol having 2 to 12 carbon atoms and adiisocyanate having 1 to 12 carbon atoms. Examples of the polyetherinclude polyethylene glycol, polypropylene glycol, polybutylene glycol,and poly(1-methylbutylene glycol). Examples of the poly(conjugateddiene) and a hydrogenated poly(conjugated diene) include1,4-polybutadiene, 1,2-polybutadiene, polyisoprene,poly(butadiene-isoprene), poly(butadiene-styrene),poly(isoprene-styrene), polyfarnesene, and hydrogenated productsthereof. Among these, a structure of a polyester is preferred from thestandpoint of the excellent toughness thereof.

Examples of the compound having an isocyanate group includehexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylenediisocyanate (XDI), diphenylmethane diisocyanate (MDI), isophoronediisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMHMDI),tricyclodecane diisocyanate (TCDDI), and adamantane diisocyanate (ADI).

Examples of the (meth)acrylate compound having a hydroxy group include ahydroxy (meth)acrylate, such as 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate,6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate,3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, glycerin mono(meth)acrylate, N-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl) (meth)acrylamide,2-hydroxy-3-acryloyloxypropyl (meth)acrylate,2,2-bis(4-(3-(meth)acryloyloxy-2-hydroxypropoxy)phenyl)propane,1,2-bis(3-(meth)acryloyloxy-2-hydroxypropoxy)ethane, pentaerythritoltri(meth)acrylate, and dipentaerythritol tri- or tetra(meth)acrylate.

In the present invention, the expression “(meth)acryloyloxy” shows themeaning encompassing both methacryloyloxy and acryloyloxy.

The addition reaction of the compound having an isocyanate group and the(meth)acrylate compound having a hydroxy group may be performedaccording to a known method, which is not particularly limited.

Examples of the urethanated (meth)acrylic compound (a)-1α obtainedinclude a reaction product of an arbitrary combination of the polyolhaving at least one structure selected from the group consisting of apolyester, a polycarbonate, a polyurethane, a polyether, apoly(conjugated diene), and a hydrogenated poly(conjugated diene), thecompound having an isocyanate group, and the (meth)acrylate compoundhaving a hydroxy group.

The weight average molecular weight (Mw) of the urethanated(meth)acrylic compound (a)-1α is preferably 1,000 to 30,000, morepreferably 1,500 to 15,000, and further preferably 2,000 to 5,000, fromthe standpoint of the viscosity and the strength. The weight averagemolecular weight (Mw) in the present invention means a weight averagemolecular weight in terms of polystyrene conversion measured by gelpermeation chromatography (GPC).

The content of the urethanated (meth)acrylic compound (a)-1α in thepresent invention is preferably 5.0 to 90.0% by mass, and is morepreferably 10.0 to 80.0% by mass, further preferably 15.0 to 70.0% bymass, and still further preferably 20.0 to 50.0% by mass, from thestandpoint of the excellent modeling capability, and the excellenttoughness and water resistance of the cured article, all based on thetotal amount of the polymerizable monomer (a) and the compound (c).

Examples of the polymerizable monomer containing plural polymerizablegroups containing no urethane bond include2,2-bis((meth)acryloyloxyphenyl)propane,2,2-bis(4-(3-acryloyloxy)-2-hydroxypropoxyphenyl)propane,2,2-bis(4-(3-methacryloyloxy)-2-hydroxypropoxyphenyl)propane (trivialname: Bis-GMA), 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane,2,2-bis(4-(meth)acyrloyloxypolyethoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxydipropoxyphenyl)propane,2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane,2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane,2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane,2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane,1,4-bis(2-(meth)acryloyloxyethyl) pyromellitate, glyceroldi(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycoldi(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycoldi(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,3-butanedioldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 2-ethyl-1,6-hexanediol di(meth)acrylate,1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane. Among these,2,2-bis(4-(3-methacryloyloxy)-2-hydroxypropoxyphenyl)propane and2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane are preferred from thestandpoint of the toughness and the curing capability.

Examples of the trifunctional or higher polymerizable monomer includetrimethylolpropane tri(meth)acrylate, trimethylolethanetri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritoltri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol penta(meth)acrylate, and1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxyheptane.

The content of the polymerizable monomer containing plural polymerizablegroups containing no urethane bond in the present invention ispreferably 0 to 40.0% by mass, and is more preferably 1.0 to 30.0% bymass, and further preferably 2.5 to 20.0% by mass, from the standpointof the excellent toughness and water resistance of the cured article,all based on the total amount of the polymerizable monomer (a) and thecompound (c).

Examples of the monofunctional polymerizable monomer (a)-2 include apolymerizable monomer containing a ring structure and a polymerizablemonomer containing no ring structure, and a ring structure is preferablycontained therein from the standpoint of the curing capability and thetoughness.

Examples of the ring structure are not particularly limited, as far asthe effects of the present invention are exhibited, and include acycloalkane series, such as a biphenyl ring, a phenoxybenzene ring, abicyclo[1.1.1]pentane ring, a (1r,4r)-bicyclo[2.1.1]hexane ring,(1s,4s)-bicyclo[2.2.1]heptane ring (trivial name: norbornane ring), abicyclo[2.2.2]octane ring, a (1r,5r)-bicyclo[3.1.1]heptane ring, a(1R,5S)-bicyclo[3.2.1]octane ring, a (1R,5S)-bicyclo[3.3.1]nonane ring,a bicyclo[3.3.2]decane ring, a bicyclo[3.3.3]undecane ring, a(1r,6r)-bicyclo[4.2.2]decane ring, (1r,6r)-bicyclo[4.3.2]undecane ring,a (1r,6r)-bicyclo[4.3.3]dodecane ring, a (1R,6S)-bicyclo[4.2.1]nonanering, a (1R,6S)-bicyclo[4.3.1]decane ring, a(3aR,4R,7S,7aS)-octahydro-1H-4,7-methanoindene ring (trivial name:dicyclopentanyl ring), a(1R,4S,4as,5R,8S)-decahydro-1,4:5,8-dimethanonapthalene ring (trivialname: tetracyclododecanyl ring), a tricyclo[1.1.0.0^(2,4)]butane ring, apentacyclo[2.1.0.0^(1,3).0^(2,4).0^(2,5)]pentane ring, atetracyclo[2.1.0^(1,3).0^(2,5)]pentane ring, aheptacyclo[2.2.0.0^(1,3).0^(2,5).0^(2,6).0^(3,5).0^(4,6)]hexane ring, anadamantane ring, a (1s,4s)-bicyclo[2.2.1]hept-2-ene ring (trivial name:norbornene ring), a (3aR,4R,7R,7aR)-hexahydro-1H-4,7-methanoindene ring(trivial name: dicyclopentenyl ring), a(1R,4S,5S,8R,8aR)-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-methanonaphthalenering (trivial name: tricyclododecanyl ring), a [1,1]paracyclophane ring,a [2,2]paracyclophane ring, a [2,2]metacyclophane ring, a[2,2,2,2](1,2,4,5)cyclophane ring, a9,10-dihydro-9,10-[1,2]benzenoanthracene ring, a cyclopentane ring, acyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononanering, a cyclodecane ring, a cyclododecane ring, a cyclohexadecane ring,a (1s,3s)-bicyclo[1.1.0]butane ring, a (1R,4S)-bicyclo[2.1.0]pentanering, a (1R,5s)-bicyclo[3.1.0]hexane ring, a(1R,5s)-bicyclo[3.2.0]heptane ring, a (3as,6as)-octahydropentalene ring,a (1R,6S)-bicyclo[4.1.0]heptane ring, a (1R,6S)-bicyclo[4.2.0]octanonering, a (3aR,7aS)-octahydro-1H-indene ring, a(4as,8as)-decahydronaphthalene ring, a (4ar,8ar)-decahydronaphthalenering, a decahydronaphthalene ring, and a tetradecahydronaphthalene ring;a cycloalkene series, such as a cyclopentene ring, a cyclohexene ring, acycloheptene ring, a cyclooctene ring, a cyclobutadiene ring, acyclopentadiene ring, a cyclohexadiene ring, a cycloheptadiene ring, acyclooctadiene ring, an octahydronaphthalene ring, and adodecahydroanthracene; a [4n+2]annulene series having 3 or more ringcarbon atoms, such as a benzene ring, a cyclooctatetraene ring, acyclotetradecaheptaene ring, and a cyclooctadecanonaene ring; anaromatic condensed bicyclic series, such as a naphthalene ring, apentalene ring, an indene ring, an indane ring, a tetralin ring, and anazulene ring; a hydrocarbon ring, for example, a carbon-condensedtricyclic series, such as an as-indacene ring, an s-indacene ring, abiphenylene ring, an acenaphthylene ring, an acenaphthene ring, afluorene ring, a phenalene ring, a perinaphthene ring, a phenanthrenering, and an anthracene ring; a heterocyclic series containing only anitrogen atom, represented by a saturated monocyclic series containingone nitrogen atom, such as an ethyleneimine ring, an azetidine ring, apyrrolidine ring, a piperidine ring, an azepane ring, a quinuclidinering, and a tropane ring; a saturated monocyclic series containing twoor more nitrogen atoms, such as a piperazine ring and a methenaminering; an unsaturated monocyclic series containing one nitrogen atom,such as an azirine ring, an azete ring, a pyrrole ring, a pyridine ring,a quinuclidine ring, and an azepine ring; an unsaturated monocyclicseries containing two or more nitrogen atoms, such as an imidazole ring,an indazole ring, an imidazoline ring, a pyrazole ring, a pyrazine ring,a pyrimidine ring, a pyridazine ring, a triazole ring, a triazine ring,and a tetrazole ring; an unsaturated polycyclic series containing onenitrogen atom, such as an indole ring, an isoindole ring, a quinolinering, an isoquinoline ring, a carbazole ring, and an acridine ring; andan unsaturated polycyclic series containing two or more nitrogen atoms,such as a benzimidazole ring, a quinoxaline ring, a quinazoline ring, aphthalazine ring, a cinnoline ring, a pteridine ring, a naphthyridinering, a purine ring, a benzotriazole ring, a phenazine ring, abenzodiazepine ring, a benzo-o-cinnoline ring, a porphyrin ring, achlorin ring, and a choline ring; and a heterocyclic series containingboth a nitrogen atom and an oxygen atom, such as a morpholine ring, alactam ring, an isatin ring, a primidone ring, an oxazine ring, anoxazole ring, an isoxazole ring, a benzoxazine ring, a phenoxazine ring,a benzophenoxazine ring, a phenazone ring, a hydantoin ring, and aphthalocyanine ring, and among these, a biphenyl ring, a phenoxybenzenering, a pyrrolidine ring, a piperidine ring, and morpholine ring arepreferred from the standpoint of the modeling capability.

Examples of the polymerizable monomer (a)-2 containing a ring structureinclude a cyclic (meth)acrylate ester compound, such as o-phenylphenol(meth)acrylate, m-phenylphenol (meth)acrylate, p-phenylphenol(meth)acrylate, methoxylated, o-phenylphenol (meth)acrylate,methoxylated m-phenylphenol (meth)acrylate, methoxylated p-phenylphenol(meth)acrylate, ethoxylated o-phenylphenol (meth)acrylate, ethoxylatedm-phenylphenol (meth)acrylate, ethoxylated p-phenylphenol(meth)acrylate, propoxylated o-phenylphenol (meth)acrylate, propoxylatedm-phenylphenol (meth)acrylate, propoxylated p-phenylphenol(meth)acrylate, butoxylated, o-phenylphenol (meth)acrylate, butoxylatedm-phenylphenol (meth)acrylate, butoxylated p-phenylphenol(meth)acrylate, o-phenoxybenzyl (meth)acrylate, m-phenoxybenzyl(meth)acrylate, p-phenoxybenzyl (meth)acrylate, 2-(o-phenoxyphenyl)ethyl(meth)acrylate, 2-(m-phenoxyphenyl)ethyl (meth)acrylate,2-(p-phenoxyphenyl)ethyl (meth)acrylate, 3-(o-phenoxyphenyl)propyl(meth)acrylate, 3-(m-phenoxyphenyl)propyl (meth)acrylate,3-(p-phenoxyphenyl)propyl (meth)acrylate, 4-(o-phenoxyphenyl)butyl(meth)acrylate, 4-(m-phenoxyphenyl)butyl (meth)acrylate,4-(p-phenoxyphenyl)butyl (meth)acrylate, 5-(o-phenoxyphenyl)pentyl(meth)acrylate, 5-(m-phenoxyphenyl)pentyl (meth)acrylate,5-(p-phenoxyphenyl)pentyl (meth)acrylate, 6-(o-phenoxyphenyl)hexyl(meth)acrylate, 6-(m-phenoxyphenyl)hexyl (meth)acrylate,6-(p-phenoxyphenyl)hexyl (meth)acrylate, 2-(1-adamantyl)propyl(meth)acrylate, 2-methyladamantyl-2-yl (meth)acrylate,2-ethyladamantyl-2-yl (meth)acrylate, 2-n-propyladamantyl-2-yl(meth)acrylate, 2-isopropyladamantyl-2-yl (meth)acrylate,1-(adamantan-1-yl)-1-methylethyl (meth)acrylate,1-(adamantan-1-yl)-1-ethylethyl (meth)acrylate,1-(adamantan-1-yl)-1-methylpropyl (meth)acrylate, and1-(adamantan-1-yl)-1-ethylpropyl (meth)acrylate; a (meth)acrylate estercompound containing a hydrocarbon ring, such as 4-biphenylyl(meth)acrylate, 2-oxo-1,2-diphenylethyl (meth)acrylate, 1-naphtyl(meth)acrylate, 2-naphtyl (meth)acrylate, 1-naphtylmethyl(meth)acrylate, 1-anthryl (meth)acrylate, 2-anthryl (meth)acrylate,9-anthryl (meth)acrylate, 9-anthrylmethyl (meth)acrylate,o-2-propenylphenyl (meth)acrylate, trityl (meth)acrylate, cyclohexyl(meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, andphenyl (meth)acrylate; a cyclic (meth)acrylate ester compound containinga nitrogen atom, such as pentamethylpiperidinyl (meth)acrylate,tetramethylpiperidinyl (meth)acrylate, and4-(pyrimidin-2-yl)piperadin-1-yl (meth)acrylate; a cyclic(meth)acrylamide compound, such as N-(meth)acryloylpyrrolidine,N-(meth)acryloylpiperidine, N-(meth)acryloyl-2-methylpiperidine, andN-(meth)acryloyl-2,2,6,6-tetramethylpiperidine; a polycyclic(meth)acrylate ester compound containing a nitrogen atom, such as2-(2′-hydroxy-5′-(meth)acryloyloxyethylphenyl)-2H-benzotriazole,2-(2′-hydroxy-5′-(meth)acryloyloxyethylphenyl)-5-chloro-2H-benzotriazole,2-(2′-hydroxy-5′-(meth)acryloyloxypropylphenyl)-2H-benzotriazole,2-(2′-hydroxy-5′-(meth)acryloyloxypropylphenyl)-5-chloro-2H-benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-(meth)acryloyloxyethylphenyl)-2H-benzotriazole,and2-(2′-hydroxy-3′-tert-butyl-5′-(meth)acryloyloxyethylphenyl)-5-chloro-2H-benzotriazole;a methacrylate ester compound having a nitrogen atom-containing6-membered ring, such as2,4-diphenyl-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2-methylphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2-methoxyphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2-ethylphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2-ethoxyphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,2,4-bis(2,4-diethoxyphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine,and2,4-bis(2,4-diethylphenyl)-6-[2-hydroxy-4-{2-(meth)acryloyloxyethoxy}]-S-triazine;a (meth)acylate ester compound having a ring structure containing anoxygen atom in addition to a nitrogen atom, such as imide(meth)acrylate, 2-(4-oxazolin-3-yl)ethyl (meth)acrylate, ethoxylatedisocyanuric acid tri(meth)acrylate, and ε-caprolactone-modifiedtris(2-acryloyloxyethyl) isocyanurate; and a cyclic acrylamide compound,such as 4-acryloylmorpholine, and among these, from the standpoint ofthe achievement of the excellent toughness and water resistance of thecured article of the resin composition for stereolithography of thepresent invention, o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate,p-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate,2-(m-phenoxyphenyl)ethyl acrylate, 2-(p-phenoxyphenyl)ethyl acrylate,N-(meth)acryloylmorpholine, pentamethylpiperidinyl (meth)acrylate, andtetramethylpiperidinyl (meth)acrylate are more preferred,o-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate,2-(o-phenoxyphenyl)ethyl acrylate, 2-(m-phenoxyphenyl)ethyl acrylate,N-(meth)acryloylmorpholine, pentamethylpiperidinyl (meth)acrylate, andtetramethylpiperidinyl (meth)acrylate are further preferred, andm-phenoxybenzyl acrylate, 2-(o-phenoxyphenyl)ethyl acrylate,N-(meth)acryloylmorpholine, and pentamethylpiperidinyl (meth)acrylateare most preferred.

The content of the monofunctional polymerizable monomer (a)-2 in thepresent invention is preferably 5.0 to 90.0% by mass, and is morepreferably 10.0 to 80.0% by mass, and further preferably 20.0 to 70.0%by mass, from the standpoint of the excellent modeling capability, andthe excellent toughness and water resistance of the cured article, allbased on the total amount of the polymerizable monomer (a) and thecompound (c).

Examples of the polymerizable monomer (a)-2 containing no ring structureinclude 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate,6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, propyleneglycol mono(meth)acrylate, glycerol mono(meth)acrylate, erythritolmono(meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,sec-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl(meth)acrylate, n-hexyl (meth)acrylate, lauryl (meth)acrylate, cetyl(meth)acrylate, stearyl (meth)acrylate, 2,3-dibromopropyl(meth)acrylate, 3-(meth)acryloyloxypropyltrimethoxysilane,11-(meth)acryloyloxyundecyltrimethoxysilane, and (meth)acrylamide.Examples of the monofunctional (meth)acrylamide based polymerizablemonomer include N,N-dimethyl (meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-di-n-propyl (meth)acrylamide, N,N-di-n-butyl(meth)acrylamide, N,N-di-n-hexyl (meth)acrylamide, N,N-di-n-octyl(meth)acrylamide, N,N-di-2-ethylhexyl (meth)acrylamide, N-hydroxyethyl(meth)acrylamide, and N,N-(dihydroxyethyl) acrylamide. These compoundsmay be used alone or as a combination of two or more kinds thereof.Among these, the (meth)acrylamide based polymerizable monomer ispreferred, and therein N-(meth)acryloylmorpholine, N,N-dimethyl(meth)acrylamide, and N,N-diethyl (meth)acrylamide are more preferred,from the standpoint of the excellent curing capability.

The curable composition of the present invention contains thepolymerizable monomer (a) in an amount of 79.0 to 99.0% by mass. In thecase where the content of the polymerizable monomer (a) is less than79.0% by mass, the modeling capability, and the toughness and the waterresistance of the cured article are deteriorated. In this standpoint,the content of the polymerizable monomer (a) in the curable compositionis preferably 82.0 to 97.0% by mass, more preferably 85.0 to 95.0% bymass, and further preferably 87.0 to 95.0% by mass.

Photopolymerization Initiator (b)

The photopolymerization initiator (b) used in the present invention maybe selected from photopolymerization initiators having been used inordinary industries, and among these, a photopolymerization initiatorused in dental purpose is preferably used.

Examples of the photopolymerization initiator (b) include a(bis)acylphosphine oxide compound, a thioxanthone compound or aquaternary ammonium salt of a thioxanthone compound, a ketal compound,an α-diketone compound, a coumarin compound, an anthraquinone compound,a benzoin alkyl ether compound, and an α-aminoketone compound. Thesecompounds may be used alone or as a combination of two or more kindsthereof.

Among these photopolymerization initiators (b), at least one kindselected from the group consisting of a (bis)acylphosphine oxidecompound and a salt thereof, and an α-diketone compound is preferablyused. With the use thereof, the resin composition for stereolithographythat is excellent in photocuring capability in the ultraviolet regionand the visible light region, and shows sufficient photocuringcapability with any light source including a laser, such as an Ar laserand a He—Cd laser, and an illumination, such as a halogen lamp, a xenonlamp, a metal halide lamp, a light emitting diode (LED), a mercury lamp,and a fluorescent lamp, can be obtained.

Examples of the acylphosphine oxide compound in the (bis)acylphosphineoxide compound used as the photopolymerization initiator (b) include2,4,6-trimethylbenzoyldiphenylphosphine oxide,2,6-dimethoxybenzoyldiphenylphosphine oxide,2,6-dichlorobenzoyldiphenylphosphine oxide,2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide,2,4,6-trimethylbenzoylethoxyphenylphosphine oxide,2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide,benzoyldi-(2,6-dimethylphenyl) phosphonate,2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt,2,4,6-trimethylbenzoyldiphenylphosphine oxide potassium salt, and2,4,6-trimethylbenzoyldiphenylphosphine oxide ammonium salt. Examples ofthe bisacylphosphine oxide compound includebis(2,6-dichlorobenzoyl)phenylphosphine oxide,bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide,bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide,bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide,bis(2,6-dimethoxybenzoyl)phenylphosphine oxide,bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide,bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide,bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, andbis(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.Examples thereof also include the compounds described in JP 2000-159621A.

Among the (bis)acylphosphine oxide compounds,2,4,6-trimethylbenzoyldiphenylphosphine oxide,2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide,bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt are particularlypreferred.

Examples of the α-diketone compound used as the photopolymerizationinitiator (b) include diacetyl, benzyl, camphorquinone, 2,3-pentadione,2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, andacenaphthenequinone. Among these, camphorquinone is particularlypreferred in the case where a light source in the visible light regionis used.

The content of the photopolymerization initiator (b) in the curablecomposition of the present invention is 0.1 to 10.0% by mass based onthe total amount of the curable composition from the standpoint of thecuring capability of the resulting resin composition forstereolithography, and the like. The content thereof is more preferably0.5% by mass or more, and further preferably 1.0% by mass or more. Inthe case where the content of the photopolymerization initiator (b)exceeds 10.0% by mass based on the curable composition, there is aconcern that the photopolymerization initiator is deposited from thecurable composition in the case where the solubility thereof is low. Thecontent of the photopolymerization initiator (b) is more preferably 7.5%by mass or less, and further preferably 5.5% by mass or less, based onthe curable composition.

Compound (c)

The compound (c) used in the present invention is a compound representedby the following general formula (I). The compound (c) has curingcapability and oxygen absorbing capability, and therefore the usethereof in the curable composition can provide a cured article withoutcuring inhibition due to oxygen.

In the general formula (I), X¹, X², and X³ each represent a chalcogenatom. X¹, X², and X³ each preferably represent an oxygen atom or asulfur atom, and more preferably an oxygen atom, from the standpoint ofthe productivity of the polymer, and the enhancement of the oxygenabsorbability.

In the general formula (I), R¹ and R² each independently represent atleast one kind selected from the group consisting of a hydrogen atom, analkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18carbon atoms, and an aralkyl group.

In R¹ and R² in the general formula (I), examples of the alkyl grouphaving 1 to 18 carbon atoms include a methyl group, an ethyl group, an-propyl group, an isopropyl group, a n-butyl group, an isobutyl group,a sec-butyl group, a tert-butyl group, a n-pentyl group, an isopentylgroup, a neopentyl group, a n-hexyl group, a n-heptyl group, anisoheptyl group, a n-octyl group, an isooctyl group, a n-nonyl group, anisononyl group, a n-decanyl group, an isodecanyl group, a n-undecanylgroup, a n-dodecanyl group, a n-tetradecanyl group, a n-hexadecanylgroup, a n-octadecanyl group, a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, a norbornyl group, an isobornylgroup, and an adamantyl group.

In R¹ and R² in the general formula (I), examples of the alkenyl grouphaving 2 to 18 carbon atoms include a vinyl group, an allyl group, apropenyl group, an isopropenyl group, a butenyl group, an isobutenylgroup, a pentenyl group, a hexenyl group, a heptenyl group, an octenylgroup, a nonenyl group, a dencanenyl group, an undecanenyl group, adodecanenyl group, a tetradecanenyl group, an octadecanenyl group, aniso-3-hexenyl group, a cyclohexenyl group, a norbornenyl group, and anisonorbornenyl group.

In R¹ and R² in the general formula (I), the aralkyl group is preferablyan aralkyl group having 7 to 18 carbon atoms, and examples thereofinclude a benzyl group, a 2-phenylethyl group, a 2-naphthylethyl group,and a diphenylmethyl group. In the aralkyl group in the presentinvention, the alkyl group moiety in the aralkyl group may contain adouble bond.

Among these, R¹ and R² each independently preferably represent at leastone kind selected from the group consisting of a hydrogen atom, an alkylgroup having 1 to 6 carbon atoms, and an alkenyl group having 2 to 6carbon atoms. Among these, R¹ preferably represents a hydrogen atom, andR² preferably represents an alkenyl group having 2 to 6 carbon atoms,and more preferably at least one kind selected from the group consistingof an isopropenyl group, a butenyl group, and an isobutenyl group, fromthe standpoint of the enhancement of the oxygen absorbability of thepolymer.

In the general formula (I), R³ and R⁴ each independently represent atleast one kind selected from the group consisting of a hydrogen atom, analkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6carbon atoms, an aryl group, and an aralkyl group.

In R³ and R⁴ in the general formula (I), examples of the alkyl grouphaving 1 to 6 carbon atoms include a methyl group, an ethyl group, an-propyl group, an isopropyl group, a n-butyl group, an isobutyl group,a sec-butyl group, a tert-butyl group, a n-pentyl group, an isopentylgroup, a neopentyl group, a n-hexyl group, a cyclopropyl group, acyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

In R³ and R⁴ in the general formula (I), examples of the alkenyl grouphaving 2 to 6 carbon atoms include a vinyl group, an allyl group, apropenyl group, an isopropenyl group, a butenyl group, an isobutenylgroup, a pentenyl group, a heptenyl group, a hexenyl group, aniso-3-hexenyl group, and a cyclohexenyl group.

In R³ and R⁴ in the general formula (I), the aryl group is preferably anaryl group having 6 to 18 carbon atoms, and examples thereof include aphenyl group, a tolyl group, a xylyl group, and a naphthyl group.

In R³ and R⁴ in the general formula (I), the aralkyl group is preferablyan aralkyl group having 7 to 18 carbon atoms, and examples thereofinclude a benzyl group, a 2-phenylethyl group, a 2-naphthylethyl group,and a diphenylmethyl group.

Among these, R³ and R⁴ each independently preferably represent at leastone kind selected from the group consisting of an alkyl group having 1to 6 carbon atoms and an alkenyl group having 2 to 6 carbon atoms, morepreferably an alkyl group having 1 to 4 carbon atoms, and furtherpreferably a methyl group.

In the general formula (I), R⁵ and R⁶ each independently represent atleast one kind selected from the group consisting of a hydrogen atom, analkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6carbon atoms, an aryl group, and an aralkyl group.

In R⁵ and R⁶ in the general formula (I), examples of the alkyl grouphaving 1 to 6 carbon atoms include a methyl group, an ethyl group, an-propyl group, an isopropyl group, a n-butyl group, an isobutyl group,a sec-butyl group, a tert-butyl group, a n-pentyl group, an isopentylgroup, a neopentyl group, a n-hexyl group, a cyclopropyl group, acyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

In R⁵ and R⁶ in the general formula (I), examples of the alkenyl grouphaving 2 to 6 carbon atoms include a vinyl group, an allyl group, apropenyl group, an isopropenyl group, a butenyl group, an isobutenylgroup, a pentenyl group, a heptenyl group, a hexenyl group, aniso-3-hexenyl group, and a cyclohexenyl group.

In R⁵ and R⁶ in the general formula (I), the aryl group is preferably anaryl group having 6 to 18 carbon atoms, and examples thereof include aphenyl group, a tolyl group, a xylyl group, and a naphthyl group.

In R⁵ and R⁶ in the general formula (I), the aralkyl group is preferablyan aralkyl group having 7 to 18 carbon atoms, and examples thereofinclude a benzyl group, a 2-phenylethyl group, a 2-naphthylethyl group,and a diphenylmethyl group.

Among these, R⁵ and R⁶ each independently preferably represent at leastone kind selected from the group consisting of a hydrogen atom, an alkylgroup having 1 to 3 carbon atoms, an alkenyl group having 2 or 3 carbonatoms, and an aryl group, more preferably a hydrogen atom or a methylgroup, and further preferably a hydrogen atom. Among these, R⁵preferably represents a hydrogen atom, and R⁶ preferably represents ahydrogen atom or a methyl group, and both of them each preferablyrepresent a hydrogen atom, from the standpoint of the enhancement of theoxygen absorbability of the polymer.

In the general formula (I), R⁷ represents a hydrogen atom or a methylgroup.

In the general formula (I), R⁸ represents at least one kind selectedfrom the group consisting of a hydrogen atom, an alkyl group having 1 to6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a(meth)acryloyl group, a 4-vinylphenyl group, an aryl group, and anaralkyl group.

In R⁸ in the general formula (I), examples of the alkyl group having 1to 6 carbon atoms include a methyl group, an ethyl group, a n-propylgroup, an isopropyl group, a n-butyl group, an isobutyl group, asec-butyl group, a tert-butyl group, a n-pentyl group, an isopentylgroup, a neopentyl group, a n-hexyl group, a cyclopropyl group, acyclobutyl group, a cyclopentyl group, a cyclohexyl group.

In R⁸ in the general formula (I), examples of the alkenyl group having 2to 6 carbon atoms include a vinyl group, an allyl group, a propenylgroup, an isopropenyl group, a butenyl group, an isobutenyl group, apentenyl group, a heptenyl group, a hexenyl group, an iso-3-hexenylgroup, and a cyclohexenyl group.

In R⁸ in the general formula (I), the aryl group is preferably an arylgroup having 6 to 18 carbon atoms, and examples thereof include a phenylgroup, a tolyl group, a xylyl group, and a naphthyl group.

In R⁸ in the general formula (I), the aralkyl group is preferably anaralkyl group having 7 to 18 carbon atoms, and examples thereof includea benzyl group, a 2-phenylethyl group, a 2-naphthylethyl group, and adiphenylmethyl group.

Among these, R⁸ preferably represents at least one kind selected fromthe group consisting of a hydrogen atom, an alkenyl group having 2 to 6carbon atoms, and a (meth)acryloyl group, and more preferably a hydrogenatom or a (meth)acryloyl group.

In the general formula (I), R³, R⁴, R⁵, and R⁶ are not bonded to eachother to form a ring structure.

In the general formula (I), n represents an arbitrary integer. Thecompound, wherein n=1, is preferred from the standpoint of the easinessin synthesis, and the like.

Specific examples of the compound represented by the general formula (I)are not particularly limited, and include the following compounds, and acompound represented by the following general formula (II) is preferredfrom the standpoint of the oxygen absorbability.

In the general formula (II), R⁹ and R¹⁰ each independently represent atleast one kind selected from the group consisting of a hydrogen atom, analkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6carbon atoms, an aryl group, and an aralkyl group; R¹¹ and R¹² eachindependently represent at least one kind selected from the groupconsisting of a hydrogen atom, an alkyl group having 1 to 6 carbonatoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, andan aralkyl group; n represents an arbitrary integer. R³, R⁴, R⁵, R⁶, R⁹,R¹⁰, R¹¹, and R¹² are not bonded to each other to form a ring structure.R³ to R⁸ have the same definitions as above.

In R⁹, R¹⁰, R¹¹, and R¹² in the general formula (II), examples of thealkyl group having 1 to 6 carbon atoms include a methyl group, an ethylgroup, a n-propyl group, an isopropyl group, a n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group,an isopentyl group, a neopentyl group, a n-hexyl group, a cyclopropylgroup, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

In R⁹, R¹⁰, R¹¹, and R¹² in the general formula (II), examples of thealkenyl group having 2 to 6 carbon atoms include a vinyl group, an allylgroup, a propenyl group, an isopropenyl group, a butenyl group, anisobutenyl group, a pentenyl group, a heptenyl group, a hexenyl group,an iso-3-hexenyl group, and a cyclohexenyl group.

In R⁹, R¹⁰, R¹¹, and R¹² in the general formula (II), the aryl group ispreferably an aryl group having 6 to 18 carbon atoms, and examplesthereof include a phenyl group, a tolyl group, a xylyl group, and anaphthyl group.

In R⁹, R¹⁰, R¹¹, and R¹² in the general formula (II), the aralkyl groupis preferably an aralkyl group having 7 to 18 carbon atoms, and examplesthereof include a benzyl group, a 2-phenylethyl group, a 2-naphthylethylgroup, and a diphenylmethyl group.

In the general formula (II), R³, R⁴, R⁹, and R¹⁰ each independentlyrepresent at least one kind selected from the group consisting of ahydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenylgroup having 2 to 6 carbon atoms, an aryl group, and an aralkyl group.Among these, R³, R⁴, R⁹, and R¹⁰ each independently preferably representat least one kind selected from the group consisting of a hydrogen atom,an alkyl group having 1 to 6 carbon atoms, and an alkenyl group having 2to 6 carbon atoms, more preferably a hydrogen atom or an alkyl grouphaving 1 to 4 carbon atoms, and from the standpoint of the availabilityof the raw material, further preferably a hydrogen atom or a methylgroup, and particularly preferably a methyl group.

In the general formula (II), R⁶ and R¹² each represent a hydrogen atomor a methyl group, and preferably a hydrogen atom.

In the general formula (II), R⁸ preferably represents at least one kindselected from the group consisting of a hydrogen atom, an alkyl grouphaving 1 to 6 carbon atoms, and a (meth)acryloyl group, and morepreferably a hydrogen atom or a (meth)acryloyl group.

In the general formula (II), n represents an arbitrary integer. Thecompound, wherein n=1, is preferred from the standpoint of the easinessin synthesis, and the like.

With the use of a compound represented by the following general formula(III) as the compound (c) of the curable composition of the presentinvention, a good curing rate can be obtained even though the curablecomposition is exposed to the air for a long period of time beforecuring.

In the general formula (III), R represents a hydrogen atom or a methylgroup; R¹, R², R³, R⁴, and R⁷ have the same definitions as above; and nrepresents an integer of 2 or more, preferably 3 or more, and morepreferably 5 or more.

The production method of the compound (c) is not particularly limited,and the compound can be produced by applying a known method alone or anappropriate combination of the known methods. For example, the compoundcan be produced by reacting a compound capable of forming a linkinggroup, such as epichlorohydrin, with 3-methyl-2-buten-1-ol, which is thecorresponding alcohol, in the presence of an alkali, such as potassiumhydroxide. The reaction condition is preferably a temperature ofapproximately 25 to 70° C. and a reaction time of approximately 2 to 10hours under agitation, from the standpoint of the sufficient reaction.

In the present invention, only one kind of the compound (c) may becontained, and two or more kinds thereof may be contained.

The content of the compound (c) in the present invention is 0.01% bymass or more, preferably 0.1% by mass or more, and more preferably 0.5%by mass or more, from the standpoint of the curing capability of theresulting resin composition for stereolithography, and the like. Thecontent thereof is 20.0% by mass or less, preferably 15.0% by mass orless, and more preferably 10.0% by mass or less, from the standpoint ofthe properties of the resulting cured article, and the like.

Inorganic Particles (d)

The curable composition of the present invention may contain inorganicparticles (d). The inorganic particles (d) may be surface-treated inadvance depending on necessity with a known surface treatment agent,such as an organic compound containing an acidic group; a fatty acidamide, such as a saturated fatty acid amide, an unsaturated fatty acidamide, a saturated fatty acid bisamide, and an unsaturated fatty acidbisamide; and an organic silicon compound, such as a silane couplingagent, for regulating the miscibility with the polymerizable monomer (a)and the compound (c). The inorganic particles (d) are preferablysurface-treated with an organic compound containing an acidic group forthe enhancement of the chemical bonding capability among thepolymerizable monomer (a), the compound (c), and the inorganic particles(d), so as to enhance the mechanical strength of the cured article.Examples of the acidic group-containing organic compound include anorganic compound having at least one group of an acidic group, such as aphosphoric acid group, a pyrophosphoric acid group, a thiophosphoricacid group, a phosphonic acid group, a sulfonic acid group, and acarboxylic acid group, and an organic compound having at least onephosphoric acid group is preferred. In the case where two or more kindsof the surface treatment agents are used, a surface treatment layer of amixture of the two or more kinds of the surface treatment agents may beused, and a surface treatment layer having a multiple layer structureincluding plural surface treatment agent layers laminated.

Examples of the acidic group-containing organic compound having aphosphoric acid group include 2-ethylhexyl acid phosphate, stearyl acidphosphate, 2-(meth)acryloyloxyethyl dihydrogen phosphate,3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyldihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate,6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyldihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate,9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyldihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate,12-(meth)acryloyloxydodecyl dihydrogen phosphate,16-(meth)acryloyloxyhexadecyl dihydrogen phosphate,20-(meth)acryloyloxyicosyl dihydrogen phosphate,bis(2-(meth)acryloyloxyethyl) hydrogen phosphate,bis(4-(meth)acryloyloxybutyl) hydrogen phosphate,bis(6-(meth)acryloyloxyhexyl) hydrogen phosphate,bis(8-(meth)acryloyloxyoctyl) hydrogen phosphate,bis(9-(meth)acryloyloxynonyl) hydrogen phosphate,bis(10-(meth)acryloyloxydecyl) hydrogen phosphate,1,3-di(meth)acryloyloxypropyl dihydrogen phosphate,2-(meth)acryloyloxyethylphenyl hydrogen phosphate,2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate,bis(2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl) hydrogen phosphate, andacid chlorides, alkali metal salts, and ammonium salts of thesecompounds.

Examples of the acidic group-containing organic compound having such anacidic group as a pyrophosphoric acid group, a thiophosphoric acidgroup, a phosphonic acid group, a sulfonic acid group, and a carboxylicacid group include the compounds described in WO 2012/042911, which maybe preferably used.

Examples of the saturated fatty acid amide include palmitic acid amide,stearic acid amide, and behenic acid amide. Examples of the unsaturatedfatty acid amide include oleic acid amide and erucic acid amide.Examples of the saturated fatty acid bisamide include ethylenebispalmitic acid amide, ethylene bisstearic acid amide, andhexamethylene bisstearic acid amide. Examples of the unsaturated fattyacid bisamide include ethylene bisoleic acid amide, hexamethylenebisoleic acid amide, and N,N′-dioleylsebacic acid amide.

Examples of the organic silicon compound include a compound representedby R¹ _(n)SiX_(4-n). In the formula, R¹ represents a saturated orunsaturated hydrocarbon group having 1 to 12 carbon atoms, X representsan alkoxy group having 1 to 4 carbon atoms, a hydroxy group, a halogenatom, or a hydrogen atom, and n represents an integer of 0 to 3,provided that in the case where plural groups exist for each of R¹ andX, the groups may be the same as or different from each other.

Specific examples thereof include methyltrimethoxysilane,dimethyldimethoxysilane, phenyltrimethoxysilane,diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane,phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane,vinyltris(β-methoxyethoxy)silane, 3,3,3-trifluoropropyltrimethoxysilane,methyl-3,3,3-trifluoropropyldimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-methacryloyloxypropylmethyldimethoxysilane,γ-methacryloyloxypropylmethyldiethoxysilane,N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane,N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane,N-β-(aminoethyl)-γ-aminopropyltriethoxysilane,γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,N-phenyl-γ-aminopropyltrimethoxysilane,γ-mercaptopropyltrimethoxysilane, trimethylsilanol,methyltrichlorosilane, methyldichlorosilane, dimethylchlorosilane,trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane,vinyltrichlorosilane, trimethylbromosilane, diethylsilane,vinyltriacetoxysilane, an ω-(meth)acryloyloxyalkyltrimethoxysilane(number of carbon atoms between (meth)acryloyloxy group and siliconatom: 3 to 12, e.g., γ-methacryloyloxypropyltrimethoxysilane), and anω-(meth)acryloyloxyalkyltriethoxysilane (number of carbon atoms between(meth)acryloyloxy group and silicon atom: 3 to 12, e.g.,γ-methacryloyloxypropyltriethoxysilane).

Among these, a silane coupling agent having a functional group capableof being copolymerized with the polymerizable monomer (a) and thecompound (c), such as an ω-(meth)acryloyloxyalkyltrimethoxysilane(number of carbon atoms between (meth)acryloyloxy group and siliconatom: 3 to 12), an ω-(meth)acryloyloxyalkyltriethoxysilane (number ofcarbon atoms between (meth)acryloyloxy group and silicon atom: 3 to 12),vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, andγ-glycidoxypropyltrimethoxysilane, is preferably used.

The method for the surface treatment may be a known method appliedthereto without particular limitation, and examples thereof include amethod of adding by spraying the surface treatment agent to theinorganic particles (d) under vigorous agitation, and a method ofdispersing or dissolving the inorganic particles (d) and the surfacetreatment agent in an appropriate solvent, followed by removing thesolvent.

The amount of the surface treatment agent used is not particularlylimited, and for example, is preferably 0.1 to 50.0 parts by mass, morepreferably 0.3 to 40.0 parts by mass, and further preferably 0.5 to 30.0parts by mass, per 100.0 parts by mass of the inorganic particles (d).

The content of the inorganic particles (d) in the present invention ispreferably 0.0 to 80.0% by mass, more preferably 1.0 to 60.0% by mass,and further preferably 5.0 to 40.0% by mass, based on the total amountof the curable composition, from the standpoint of the viscosity of theresulting resin composition for stereolithography and the modelingaccuracy and the toughness of the cured article.

The curable composition of the present invention is not particularlylimited, as far as the curable composition contains the polymerizablemonomer (a), the photopolymerization initiator (b), and the compound (c)described above, may contain the inorganic particles (d) depending onnecessity, and for example, may further contain an additional componentother than these. The content of the additional component in the curablecomposition (i.e., the component other than the polymerizable monomer(a), the photopolymerization initiator (b), the compound (c), anddepending on necessity the inorganic particles (d)) may be less than 3%by mass, may be less than 2% by mass, and may be less than 1% by mass.The curable composition and the resin composition for stereolithographyof the present invention may be produced according to a known method.

The curable composition of the present invention may contain an organicultraviolet ray absorbent for the further enhancement of the modelingaccuracy.

Examples of the organic ultraviolet ray absorbent include abenzotriazole based compound, a benzophenone based compound, and athiophene based compound. The benzotriazole based compound is preferablya compound having a hydroxy group bonded to the 2-position of thearomatic ring bonded to the nitrogen atom of the triazole structure, andfrom the stand point of more excellent modeling accuracy, morepreferably a compound having a hydroxy group bonded to the 2-position ofthe aromatic ring bonded to the nitrogen atom of the triazole structure,and an alkyl group having 1 to 10 carbon atoms bonded to the 3-positionand/or the 5-position of the aromatic ring. Examples of thebenzotriazole based compound include2-(2-hydroxy-5-methylphenyl)benzotriazole (“TINUVIN P”),2-(2-hydroxy-5-tert-octylphenyl)benzotriazole (“TINUVIN 329”),2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)benzotriazole,2-(2′-hydroxy-5′-tert-butylphenyl)benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-3′,5′-di-tert-amylphenyl)benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole, and2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzotriazole. Examplesof the benzophenone based compound include 2,4-dihydroxybenzophenone,2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone,2-hydroxy-4-(dodecyloxy)benzophenone,2-hydroxy-4-(octadecyloxy)benzophenone,2,2′-dihydroxy-4-methoxybenzophenone, and2,2′-dihydroxy-4,4′-dimethoxybenzophenone. Examples of the thiophenebased compound include 2,5-bis(5-t-butyl-2-benzoxazolyl)thiophene. Amongthese, a benzotriazole based compound is preferred from the standpointof the achievement of the good modeling accuracy.

The organic ultraviolet ray absorbent may be used alone or as acombination of two or more kinds thereof. The content of the organicultraviolet ray absorbent is preferably in a range of 0.001 to 10.0% bymass, more preferably in a range of 0.01 to 5.0% by mass, and furtherpreferably 0.1 to 2.5% by mass, based on the total amount of the curablecomposition.

The curable composition of the present invention may contain apolymerization accelerator in a range that does not impair the effectsof the present invention, for the purpose of enhancing the photocuringcapability. Examples of the polymerization accelerator include ethyl4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate,n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-(methacryloyloxy)ethyl4-N,N-dimethylaminobenzoate, 4-(N,N-dimethylamino)benzophenone, andbutyl 4-(N,N-dimethylamino)benzoate. Among these, at least one selectedfrom the group consisting of ethyl 4-(N,N-dimethylamino)benzoate,n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and4-(N,N-dimethylamino)benzophenone is preferably used from the standpointthat excellent curing capability is imparted to the resin compositionfor stereolithography.

The curable composition of the present invention may contain a knownstabilizer for the purpose of suppressing the deterioration andregulating the photocuring capability. Examples of the stabilizerinclude a polymerization inhibitor and an antioxidant.

Examples of the polymerization inhibitor include hydroquinone,hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinonemonomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol,2,6-di-t-butylphenol, and 3,5-di-t-butyl-4-hydroxytoluene. The contentof the polymerization inhibitor is preferably 0.001 to 2.0 parts by massper 100.0 parts by mass in total of the polymerizable monomer (a).

The resin composition for stereolithography of the present invention maycontain a known additive for the purpose of regulating the color toneand the paste property. Examples of the additive include a pigment, adye, an organic solvent, and a thickener.

The resin composition for stereolithography of the present invention notonly is readily modeled with low viscosity, but also has good modelingaccuracy, and a stereolithography resin cured article obtained by curingthe resin composition for stereolithography is excellent in toughnessand water resistance. Accordingly, the resin composition forstereolithography of the present invention can be applied to suchpurposes that can exploit these advantages, and for example, can beapplied to various stereoscopic modeled articles produced by the opticalstereoscopic modeling method. Among these, the resin composition forstereolithography can be preferably applied to a dental material, adental mouthpiece, a denture base material, a medical material, and asleep apnea syndrome treatment device, and is particularly optimum as adental mouthpiece and a denture base material.

As another embodiment, the present invention relates to a method forproducing a stereoscopic modeled article by the suspension opticalstereoscopic modeling method using any of the resin compositions forstereolithography described above.

In the optical stereoscopic modeling performed with the resincomposition for stereolithography of the present invention, any of theknown suspension optical stereoscopic modeling methods and the knownapparatuses therefor may be used. Among these, in the present invention,the method and apparatus using an activation energy ray as light energyfor curing the resin are preferably used. The “activation energy ray”referred in the present invention means an energy ray capable of curingthe photocurable resin composition, such as an ultraviolet ray, anelectron beam, an X-ray, a radioactive ray, and a high frequency wave.For example, the activation energy ray may be an ultraviolet ray havinga wavelength of 300 to 400 nm. Examples of the light source of theactivation energy ray include a laser, such as an Ar laser and a He—Cdlaser, and an illumination, such as a halogen lamp, a xenon lamp, ametal halide lamp, an LED, a mercury lamp, and a fluorescent lamp, and alaser is particularly preferred. In the case where a laser is used asthe light source, the modeling time can be shortened by increasing theenergy level, and furthermore a stereoscopic modeled article having highmodeling accuracy can be obtained by the good light focusing capabilityof laser light.

In the optical stereoscopic modeling performed with the resincomposition for stereolithography of the present invention, any of theknown methods and the known stereolithography apparatuses may be usedwithout particular limitation, as described above, and representativeexamples of the optical stereoscopic modeling method that is preferablyused in the present invention include a method of providing a targetstereoscopic modeled article by repeating an operation including a stepof providing a cured layer by irradiating the resin composition foroptical stereoscopic modeling with an activation energy ray selectivelyto provide the cured layer having a target pattern, and then a step ofsuspending the cured layer, supplying the uncured composition foroptical stereoscopic modeling in the form of liquid, and irradiating thecomposition similarly with an activation energy ray, so as to provide anew cured layer continuous to the cured layer. The stereoscopic modeledarticle thus obtained may be used immediately, or in some cases, may beused after enhancing the mechanical characteristics or the dimensionalstability thereof by performing post-curing by light irradiation orpost-curing by heating.

Examples

The present invention will be then described more specifically withreference to examples, but the present invention is not limited to theexamples, and many changes may be made therein within the scope of thetechnical concept of the present invention by a skilled person in thisfield of art.

The evaluation methods used in Synthesis Examples and Examples aredescribed below.

Measurement of Weight Average Molecular Weight by GPC

The measurement was performed with columns: TSK-gel SUPER HZM-H (tradename, produced by Tosoh Corporation, 4.6 mm×150 mm)×2 and TSK-gel SUPERHZ2000 (produced by Tosoh Corporation, 4.6 mm×150 mm)×1, connected inseries, eluent: tetrahydrofuran, and calibration curve: polystyrenestandard.

Analysis of Molecular Structure by NMR

The measurement was performed with ULTRASHIELD 400 PLUS (trade name,produced by Bruker Corporation).

The components used in the resin compositions for stereolithographyaccording to Examples and Comparative Examples are shown below alongwith the abbreviations thereof.

Polymerizable Monomer (a)-1

D26E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (produced byShin-Nakamura Chemical Co., Ltd.)

Polymerizable Monomer (a)-1α

A polymerizable monomers (a)-1α-1 and (a)-1α-2 produced in SynthesisExamples 1 and 2 described later were used.

Polymerizable Monomer (a)-2

EPPA: ethoxylated, o-phenylphenol acrylate (produced by Shin-NakamuraChemical Co., Ltd.)

POBA: m-phenoxybenzyl methacrylate (produced by Kyoeisha Chemical Co.,Ltd.)

ACMO: N-acryloylmorpholine (produced by KJ Chemicals Corporation)

Photopolymerization Initiator (b)

TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide

BAPO: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

Compound (c)

C-1: 1,3-bis(3-methyl-2-butenoxy)-2-methacryloxypropane (produced byKuraray Co., Ltd.)

C-2: 1,3-bis(3-methyl-2-butenoxy)-2-hydroxypropane (produced by KurarayCo., Ltd.)

C-3:α-(3-methyl-2-butenoxy)-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]

C-4:α-methoxy-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]

C-5:α-(3-methyl-2-butenoxy)-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]

C-6:α-methoxy-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]

Inorganic Particles (d)

Ar130: Aerosil 130

Polymerization Inhibitor

BHT: 3,5-di-t-butyl-4-hydroxytoluene

Synthesis Example 1 Production of Polymerizable Monomer (a)-1α-1

(1) 250 g of isophorone diisocyanate and 0.15 g of di-n-butyltindilaurate were added to a four-neck flask having a capacity of 5 Lequipped with an agitator, a temperature controller, a thermometer, anda condenser, and heated to 70° C. under agitation.

(2) Separately, 2,500 g of a polyester polyol (“KURARAY POLYOL (tradename) P-2050”, produced by Kuraray Co., Ltd., a polyol formed of sebacicacid and 3-methylpentanediol, weight average molecular weight: 2,000g/mol) was added to a dropping funnel having a side tube, and the liquidin the dropping funnel was added dropwise to the flask in the item (1)above. The dropwise addition was performed at a constant rate over 4hours while retaining the inner temperature of the flask to 65 to 75° C.under agitation of the solution in the flask in the item (1) above.After completing the dropwise addition, the reaction was performed atthe same temperature for 2 hours under agitation.

(3) Subsequently, a liquid obtained by dissolving uniformly 150 g of2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether wasadded to another dropping funnel and added dropwise at a constant rateto the flask having an inner temperature retained to 55 to 65° C. over 2hours, and then the reaction was performed for 4 hours while retainingthe temperature of the solution in the flask to 70 to 80° C., so as toprovide a polymerizable monomer (a)-1α-1. The weight average molecularweight of the polymerizable monomer (a)-1α-1 by the GPC analysis was2,600 g/mol.

Synthesis Example 2 Production of Polymerizable Monomer (a)-1α-2

(1) 250 g of isophorone diisocyanate and 0.15 g of di-n-butyltindilaurate were added to a four-neck flask having a capacity of 5 Lequipped with an agitator, a temperature controller, a thermometer, anda condenser, and heated to 70° C. under agitation.

(2) Separately, 2,500 g of a polyester polyol (“KURARAY POLYOL (tradename) P-2030”, produced by Kuraray Co., Ltd., a polyol formed ofisophthalic acid and 3-methylpentanediol, weight average molecularweight: 2,000 g/mol) was added to a dropping funnel having a side tube,and the liquid in the dropping funnel was added dropwise to the flask inthe item (1) above. The dropwise addition was performed at a constantrate over 4 hours while retaining the inner temperature of the flask to65 to 75° C. under agitation of the solution in the flask in the item(1) above. After completing the dropwise addition, the reaction wasperformed at the same temperature for 2 hours under agitation.

(3) Subsequently, a liquid obtained by dissolving uniformly 150 g of2-hydroxyethyl acrylate and 0.4 g of hydroquinone monomethyl ether wasadded to another dropping funnel and added dropwise at a constant rateto the flask having an inner temperature retained to 55 to 65° C. over 2hours, and then the reaction was performed for 4 hours while retainingthe temperature of the solution in the flask to 70 to 80° C., so as toprovide a polymerizable monomer (a)-1α-2. The weight average molecularweight of the polymerizable monomer (a)-1α-2 by the GPC analysis was2,700 g/mol.

Synthesis Example 3 Synthesis ofα-(3-methyl-2-butenoxy)-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)](C-3)

1,654 g of 3-methyl-2-buten-1-ol (produced by Kuraray Co., Ltd., 19.2mol), 1,842 g of a 50% sodium hydroxide aqueous solution (produced byKanto Chemical Co., Inc., 23.0 mol), 28 g ofdodecylbenzyldimethylammonium chloride (produced by Tokyo Kasei KogyoCo., Ltd., 0.084 mol) were charged under a nitrogen stream to a reactorequipped with an agitator, a thermometer, and a dropping funnel. Whileretaining the inner temperature to 60° C. or less, 1,776 g ofepichlorohydrin (produced by Fujifilm Wako Pure Chemical Corporation,19.2 mol) was added dropwise thereto under agitation, and aftercompleting the dropwise addition, the temperature was increased to 90°C. The reaction liquid was agitated for 9 hours at an inner temperatureof 90° C., and then cooled to 25° C. The reaction liquid was rinsed with5,000 g of a 7.5% sodium hydrogen carbonate aqueous solution, and thenthe upper layer was rinsed with 5,000 mL of ion exchanged water. Waterand unreacted 3-methyl-2-buten-1-ol were distilled off from theresulting organic layer by distillation, so as to provide 1,996 g ofα-(3-methyl-2-butenoxy)-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]represented by the formula (C-3) (yield: 73%). The GPC measurementrevealed that the compounds of n=2 to 7 in the formula (C-3) werecontained.

¹H-NMR (270 MHz, CDCl₃, TMS) δ: 5.37-5.32 (m, 5H), 4.02-3.99 (brd, 10H),3.68-3.56 (m, 4H), 3.55-3.40 (m, 10H), 2.54 (d, J=3.8 Hz, 1H), 1.74(brs, 15H), 1.66 (brs, H)

GPC measurement: number average molecular weight: 300 g/mol, weightaverage molecular weight: 360 g/mol (polystyrene conversion)

Synthesis Example 4 Synthesis of1-(3-methyl-2-butenoxy)-2,3-epoxypropane

324 g of 3-methyl-2-buten-1-ol (produced by Kuraray Co., Ltd., 3.77mol), 2,300 mL of cyclohexane, 226 g of sodium hydroxide (produced byFujifilm Wako Pure Chemical Corporation, 5.65 mol), 15.2 g oftrioctylmethylammonium chloride (produced by Tokyo Kasei Kogyo Co.,Ltd., 37.3 mmol), and 226 mL of purified water were charged under anitrogen stream to a reactor equipped with an agitator, a thermometer,and a dropping funnel. While retaining the inner temperature to 25° C.or less, 698 g of epichlorohydrin (produced by Fujifilm Wako PureChemical Corporation, 7.54 mol) was added dropwise thereto over 90minutes under agitation, and after completing the dropwise addition, thetemperature was increased to 40° C. over 30 minutes. The reaction liquidwas agitated for 3 hours at an inner temperature of 40° C., and thencooled to 25° C. The upper layer of the reaction liquid was rinsed 5times with 670 mL of a saturated salt solution, and the organic layerwas dried over sodium sulfate. Sodium sulfate was filtered out, and thefiltrate was concentrated to provide 536 g of a concentrate. Theconcentrate was purified by distillation to provide 242 g of1-(3-methyl-2-butenoxy)-2,3-epoxypropane represented by theaforementioned formula (1.67 mol, yield: 44%). The ¹H-NMR measurementresult thereof is shown below.

¹H-NMR (400 MHz, CDCl₃, TMS) δ: 5.35 (tquin, J=6.8, 1.2 Hz, 1H), 4.03(ddd, J=19.6, 12.0, 7.2 Hz, 2H), 3.68 (dd, J=11.6, 3.2 Hz, 1H), 3.99(dd, J=11.2, 5.6 Hz, 1H), 3.17-3.13 (m, 1H), 2.79 (dd, J=4.8, 4.0 Hz,1H), 2.60 (dd, J=5.2, 2.8 Hz, 1H), 1.75 (s, 3H), 1.68 (s, 3H)

Synthesis Example 5 Synthesis ofα-methoxy-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)](C-4)

20 g of 1-(3-methyl-2-butenoxy)-2,3-epoxypropane (0.14 mol) and 76 mg ofsodium methoxide (produced by Fujifilm Wako Pure Chemical Corporation,1.4 mmol) were charged under a nitrogen stream to a reactor equippedwith an agitator, a thermometer, and a dropping funnel. After increasingthe inner temperature to 110° C. and agitating for 9 hours, the reactionliquid was cooled to 25° C. After adding 1 mL of acetic acid to thereaction liquid, the low boiling point components were distilled offunder reduced pressure with an evaporator, so as to provide 18.8 g ofα-methoxy-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]represented by the aforementioned formula (C-4) (yield: 94%).

¹H-NMR (270 MHz, CDCl₃, TMS) δ: 5.34 (t, J=13.0 Hz, 47H), 4.05-3.90(brd, 94H), 3.77-3.35 (m, 235H), 2.61 (brs, 1H), 1.74 (brs, 282H), 1.67(brs, 282H)

Synthesis Example 6 Synthesis ofα-(3-methyl-2-butenoxy)-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)](C-5)

5.0 g ofα-(3-methyl-2-butenoxy)-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)],2.34 g of triethylamine (produced by Tokyo Kasei Kogyo Co., Ltd., 22.5mmol), and 20 mL of acetonitrile (produced by Fujifilm Wako PureChemical Corporation) were charged under a nitrogen stream to a reactorequipped with an agitator, a thermometer, and a dropping funnel. Whileretaining the inner temperature to 20° C. or less, 2.03 g of methacrylicchloride (produced by Fujifilm Wako Pure Chemical Corporation, 1.87mmol) was added dropwise thereto under agitation, followed by agitatingfor 5 hours. After completing the reaction, 93.6 mg ofN,N-dimethyl-4-aminopyridine (produced by Tokyo Kasei Kogyo Co., Ltd.,0.78 mmol) and 2 g of water were added thereto, followed by agitatingfor 3 hours. After adding 20 mL of ethyl acetate, the reaction liquidwas rinsed 3 times with 20 mL of a 4% by weight hydrochloric acid, 3times with 20 mL of a 6% by weight NaHCO₃ aqueous solution, and oncewith 20 mL of a saturated salt solution. Water and the solvent wereremoved from the resulting organic layer by distillation, so as toprovide 4.4 g ofα-(3-methyl-2-butenoxy)-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)]represented by the aforementioned formula C-5. The GPC measurementrevealed that the compounds of n=2 to 7 in the formula (C-5) werecontained.

¹H-NMR (270 MHz, CDCl₃, TMS) δ: 5.68 (brd, 2H), 5.36-5.33 (m, 8H),4.03-3.97 (brd, 15H), 3.70-3.51 (m, 6H), 3.55-3.37 (m, 15H), 1.73 (brs,23H), 1.66 (brs, 23H)

Synthesis Example 7 Synthesis ofα-methoxy-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethane-1,2-diyl)](C-6)

4.8 g ofα-methoxy-ω-hydroxypoly[oxy(3-methyl-2-butenoxymethylethan-1,2-diyl)],0.15 g of triethylamine (produced by Tokyo Kasei Kogyo Co., Ltd., 1.44mmol), and 10 mL of acetonitrile (produced by Fujifilm Wako PureChemical Corporation) were charged under a nitrogen stream to a reactorequipped with an agitator, a thermometer, and a dropping funnel. Whileretaining the inner temperature to 20° C. or less, 0.13 g of methacrylicchloride (produced by Fujifilm Wako Pure Chemical Corporation, 0.12mmol) was added dropwise thereto under agitation, followed by agitatingfor 5 hours. After completing the reaction, 6 mg ofN,N-dimethyl-4-aminopyridine (produced by Tokyo Kasei Kogyo Co., Ltd.,0.05 mmol) and 1 g of water were added thereto, followed by agitatingfor 3 hours. After adding 20 mL of ethyl acetate, the reaction liquidwas rinsed 3 times with 20 mL of a 4% by weight hydrochloric acid, 3times with 20 mL of a 6% by weight NaHCO₃ aqueous solution, and oncewith 20 mL of a saturated salt solution. Water and the solvent wereremoved from the resulting organic layer by distillation, so as toprovide 4.7 g ofα-methoxy-ω-methacryloxypoly[oxy(3-methyl-2-butenoxymethylethane-1,2-diyl)]represented by the aforementioned formula C-6 (yield: 95%).

¹H-NMR (400 MHz, CDCl₃, TMS) δ: 5.69 (brd, 2H), 5.33 (brd, 65H),4.01-3.88 (s, 141H), 3.82-3.34 (m, 363H), 1.73 (brs, 209H), 1.65 (brs,209H)

Examples 1 to 14 and Comparative Examples 1 to 4

The components in amounts shown in Tables 1 and 2 were mixed at ordinarytemperature (20° C.±15° C., JIS Z8703:1983), so as to provide pastes asresin compositions for stereolithography according to Examples 1 to 14and Comparative Examples 1 to 4.

Modeling Capability

The resin compositions for stereolithography according to Examples andComparative Examples each were modeled to provide a test piece of 2.0 mmin thickness×20.0 mm in width×and 60.0 mm in length, with astereolithography machine (DIGITALWAX (trade name) 020D, produced by DWSSystems Inc.). The case where a sheet having the prescribed dimensioncould be modeled with an error of 0.25 mm or less for each edge wasdesignated as modeling capability “A”, the case where a sheet having theprescribed dimension could be modeled with an error of 0.5 mm or lessfor each edge was designated as modeling capability “B”, and the casewhere the error was more than 0.5 mm for each edge, or a stereoscopicmodeled article was not obtained was designated as modeling capability“X”. The test pieces thus modeled each were subjected to the evaluationshown below. With the modeling capability “B” or better, there is apossibility that the toughness can be improved by controlling the shape,and the resin composition can be used as a denture base material.

Toughness (Hand Flex Test)

For each of cured articles of the resin compositions forstereolithography according to Examples and Comparative Examples, theaforementioned test piece (length: 60.0 mm, width: 20.0 mm, thickness(height): 2.0 mm) was evaluated by a hand flex test. Specifically, thetest piece was folded in half and then opened by hand, and the operationwas repeated. In this test, the preferred was no breakage, the casewhere the test piece was not broken after repetition of 10 times wasdesignated as good toughness “A”, the case where the test piece wasbroken after repetition of 3 to 10 times was designated as mediumtoughness “B”, and the case where the test piece was broken afterrepetition of less than 3 times was designated as poor toughness “C”.

A Hardness (Flexibility Test)

For each of cured articles of the resin compositions forstereolithography according to Examples and Comparative Examples, twosheets of the aforementioned test piece were overlapped to a thicknessof 4 mm, and the hardness (A hardness) at 23° C. of the cured articlewas measured with a type A durometer according to JIS K7215:1986, anddesignated as the index of flexibility. In the case where the A hardnessat 23° C. is 70 to 90 in this test, the cured article has flexibilitysuitable for a dental mouthpiece and a denture base material.

Water Resistance

For each of cured articles of the resin compositions forstereolithography according to Examples and Comparative Examples, thetest piece was immersed in water at 37° C. for 24 hours, and thenmeasured for the A hardness in the same manner as above. The case wherethe decrease of the hardness after the immersion in water at 37° C. for24 hours with respect to the initial hardness is 3 points or less isexcellent in water resistance.

TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 For- (a)-1 D26E 10.014.0 5.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 mulation(a)-1α-1 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 20.0 55.0 20.0 (part by(a)-1α-2 40.0 40.0 45.0 mass) (a)-2 EPPA 45.0 45.0 45.0 45.0 45.0 45.045.0 45.0 60.0 30.0 45.0 60.0 POBA 45.0 40.0 ACMO 5.0 5.0 5.0 (b) TPO5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 3.0 5.0 5.0 5.0 5.0 BAPO 0.5 (c)(C-1) 5.0 1.0 10.0 5.0 5.0 5.0 5.0 10.0 5.0 (C-2) 5.0 (C-3) 5.0 (C-4)5.0 (C-5) 5.0 (C-6) 5.0 (d) Ar380 5.0 BHT 1.0 1.0 1.0 1.0 1.0 1.0 1.01.0 1.0 1.0 1.0 1.0 1.0 1.0 Content of (a) (% by mass) 89.6 93.4 84.989.6 89.6 89.6 89.6 89.6 89.2 91.3 89.6 89.6 84.9 85.6 Content of (b) (%by mass) 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 5.2 2.9 4.7 4.7 4.7 4.5 Contentof (c) (% by mass) 4.7 0.9 9.4 4.7 4.7 4.7 4.7 4.7 4.7 4.8 4.7 4.7 9.44.5 Eval- Modeling A A A A B A A A A A A A A A uation capabilityToughness A A A A B B B B A A A A A A (hand flex test) A hardness 78 8377 76 84 82 84 82 78 80 85 84 84 82 (flexibility test) Water resistance78 82 78 75 83 84 82 84 76 79 85 83 81 81 (hardness after immersion)

TABLE 2 Comparative Example 1 2 3 4 Formulation (a)-1 D26E 15.0 15.015.0 15.0 (part by (a)-1α-1 40.0 55.0 20.0 mass) (a)-1α-2 40.0 (a)-2EPPA 45.0 45.0 30.0 60.0 ACMO 5.0 (b) TPO 5.0 5.0 5.0 5.0 (d) Ar130 10.0BHT 1.0 1.0 1.0 1.0 Content of (a) (% by mass) 51.9 51.9 66.0 30.2Content of (b) (% by mass) 42.5 42.5 28.3 56.0 Content of (c) (% bymass) 0.0 0.0 0.0 0.0 Evaluation Modeling A A X X capability Toughness CC — — (hand flex test) A hardness 82 94 — — (flexibility test) Waterresistance 75 91 — — (hardness after immersion)

As shown in Tables 1 and 2, the resin compositions for stereolithographyin Examples 1 to 14 were excellent in modeling capability. Furthermore,the cured articles thereof were excellent in toughness and waterresistance. In particular, the toughness and the water resistance of thecured articles of the resin compositions for stereolithography accordingto Examples 1 to 14 were excellent as compared to the cured articles ofthe resin compositions according to Comparative Examples 1 and 2 thatdid not contain the compound (c) of the present invention. The modelingcapability of the resin compositions for stereolithography according toExamples 1 to 14 was excellent as compared to the resin compositionsaccording to Comparative Examples 3 and 4. In Comparative Examples 3 and4, modeling was difficult due to the increase in viscosity.

Industrial Applicability

The resin composition for stereolithography of the present invention isreadily modeled with low viscosity in modeling by stereolithography andis excellent in modeling accuracy, and therefore is favorable as adental material, particularly a dental modeling material.

The invention claimed is:
 1. A curable composition comprising: 79.0 to99.0% by mass of a polymerizable monomer (a), 0.1 to 10.0% by mass of aphotopolymerization initiator (b), and 0.01 to 20.0% by mass of acompound (c) represented by the following general formula (III):

wherein: R represents a hydrogen atom or a methyl group; R¹ and R² eachindependently represents at least one selected from the group consistingof a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, analkenyl group having 2 to 18 carbon atoms, and an aralkyl group; R³ andR⁴ each independently represents at least one selected from the groupconsisting of a hydrogen atom, an alkyl group having 1 to 6 carbonatoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, andan aralkyl group; R⁷ represents a hydrogen atom or a methyl group; and nrepresents an integer of 2 or more.
 2. The curable composition accordingto claim 1, wherein the polymerizable monomer (a) contains apolymerizable monomer (a)-1 containing plural polymerizable groups. 3.The curable composition according to claim 2, wherein the polymerizablemonomer (a)-1 contains a urethanated (meth)acrylic compound (a)-1α. 4.The curable composition according to claim 1, wherein the polymerizablemonomer (a) contains a monofunctional polymerizable monomer (a)-2. 5.The curable composition according to claim 4, wherein the monofunctionalpolymerizable monomer (a)-2 contains a ring structure.
 6. A resincomposition for stereolithography comprising the curable compositionaccording to claim
 1. 7. The resin composition for stereolithographyaccording to claim 6, wherein the resin composition further comprisesinorganic particles (d).
 8. A stereolithography resin cured articlecomprising a cured article of the resin composition forstereolithography according to claim
 6. 9. A dental material comprisinga cured article of the resin composition for stereolithography accordingto claim
 6. 10. A dental mouthpiece comprising a cured article of theresin composition for stereolithography according to claim
 6. 11. Adenture base material comprising a cured article of the resincomposition for stereolithography according to claim
 6. 12. A medicalmaterial comprising a cured article of the resin composition forstereolithography according to claim
 6. 13. A sleep apnea syndrometreatment device comprising a cured article of the resin composition forstereolithography according to claim
 6. 14. A method for producing astereoscopic modeled article by an optical stereoscopic modeling method,comprising using the resin composition for stereolithography accordingto claim
 6. 15. A compound represented by the following general formula(III):

wherein: R represents a hydrogen atom or a methyl group; R¹ and R² eachindependently represents at least one selected from the group consistingof a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, analkenyl group having 2 to 18 carbon atoms, and an aralkyl group; R³ andR⁴ each independently represents at least one selected from the groupconsisting of a hydrogen atom, an alkyl group having 1 to 6 carbonatoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, andan aralkyl group; R⁷ represents a hydrogen atom or a methyl group; and nrepresents an integer of 2 or more.